• Title/Summary/Keyword: 저항 시험

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The Development of Steel-plate Concrete Panels with Preplaced Lightweight Aggregates Concrete (프리플레이스트 경량골재 콘크리트를 사용한 합성형 구조모듈 제작 및 성능 평가)

  • Yoon, Jin Young;Kim, Jae Hong
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.1
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    • pp.21-28
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    • 2017
  • The steel-plate concrete(SC) is used in a form of module assembly construction in the outer wall of nuclear-power plant and LNG containment. Since the steel-plate concrete modules are generally manufactured from the plant, the weight of SC has significantly effect on the total construction cost in the aspect of shipment. Therefore, the use of lightweight aggregates concrete(LWAC), which fill the inside of SC module can be a solution. However, the amount of used lightweight aggregates(LWA) is limited in the use of current concrete mixing process due to the concrete quality problems and it also determines the allowable minimum density of LWAC. In this research, the preplaced casting method is applied because of increasing the volume fraction of LWA significantly, which results from the producing process of pre-packing the LWA in the formwork and filling the interstitial voids between LWA using cement paste grout. The density and compressive strength of selected preplaced LWAC were $1,600kg/m^3$ and 30MPa and it was applied for the mock-up specimens of SC panel. It was used for the 3-point bending test for evaluating its structural performance. The results show that the preplaced LWAC can reduce the density of concrete with the adequate mechanical and structural performance.

Electricity Production by Metallic and Carbon Anodes Immersed in an Estuarine Sediment (퇴적토에 담지된 금속 및 탄소전극에 의한 전기 생산 특성)

  • Song, Hyung-Jin;Rhee, In-Hyoung;Kwon, Sung-Hyun;Cho, Dae-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.12
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    • pp.3731-3739
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    • 2009
  • One-chambered sediment cells with a variety of anodic electrodes were tested for generation of electricity. Material used for anodes was iron, brass, zinc/iron, copper and graphite felt which was used for a common cathode. The estuarine sediment served as supplier of oxidants or electron-producing microbial habitat which evoked electrons via fast metal corrosion reactions or a complicated microbial electron transfer mechanism, respectively. Maximum power density and current density were found to be $6.90\;W/m^2$ (iron/zinc) and $7.76\;A/m^2$ (iron), respectively. Interestingly, copper wrapped with carbon cloth produced better electric performance than copper only, by 60%, possibly because the cloth not only prevented rapid corrosion on the copper surface by some degrees, but also helped growing some electron-emitting microbes on its surface. At anodes oxidation reduction potential(ORP) was kept to be stationary over time except at the very initial period. The pH reduction in the copper and copper/carbon electrodes could be a sign of organic acid production due to a chemical change in the sediment. The simple estimation of interfacial, electrical resistances of electrodes and electrolyte in the sediment cell that a key to the electricity generation should be in how to control corrosion rate or microbial electron transfer activity.

Effect of Recovery of Pulmonary Function in Hypothermic Lung Preservation (肺의 低溫保存法이 肺機能 回復에 미치는 영향)

  • Lee, Man Bok;Kim, U Jong;Gang, Chang Hui;Lee, Gil No
    • Journal of Chest Surgery
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    • v.30 no.3
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    • pp.253-253
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    • 1997
  • Hypothermia during lung preservation decreases metabolic processes. After the rabbit lung was flushed with modified Euro-Collins solution, heart-lung block was harvested and the left lung was assessed after ligation of the right pulmonary artery and right main-stem bronchus. Heart-lung block was immersed in the same solution for 6 hours. The modified Euro-Collins solution and storage temperature of group 1(10 cases) was 4t, roup 2(10 cases) was l0℃. On completion of the storage period, the left lung was ventilated and reperfused with blood u:high used a cross-circulating paracorporeal rabbit as a "biologic deoxygenator" for 60 minutes. Pulmonary artery pressure, airway pressure, difference in oxygen tension between mow and outflow perfusate and degree of pulmonary edema were assessed at 10-minute intervals while the left lung was ventilated at 0.8 of the inspired oxygen fraction. The mean pulmonary venous oxygen tensions at 10 and 60 minutes after reperfusion were 209.52±42.46 and 103.48± 15.96 mmHg in group I versus 247.78±36.19 and 147.91 ± 11.07 mmHg in group II(p=0.049, (0.0001). The mean alveolar-arterial oxygen differences at 20 and 60 minutes after reperfusion were 357. 95± 12.84 and 437.31 14.26 mmHg in group I versus 310.88±3).47 and )90.93± 15.86 mmHg in group II (p=0.0092, (0.0001). The mean pulmonary arterial pressures at 10 and 60 minutes after reperfusion were 40.56± 18.66 and 87. 2± 17.22 mmHg in group I versus 31.22±6.84 and 65.78± 11.02 mmHg in group rl (p : 0.048, 0.0062). The mean pulmonary vascular resistances at 10 and 60 minutes after reperfusion were 2.69±0.85 and 4.36±0.86 mmHg/ml/min in group I versus 1.99±0.39 and 3.29±0.55 mmHg/ml/min in group II(p : 0.0323, 0.0062). There were no difference between groups in peak airway pressure, lung compliance and degree of pulmonary edema. In conclusion that preservation of lung at l0℃ was superior to preservation at 4℃.

Studies on the Response of Barley Varieties to Nitrogen Application and Seeding Methods (보리의 안전증수를 위한 질소비료의 효율적 이용에 관한 연구)

  • Hong-Suk Lee;Eun-Woong Lee;Ho-Young Lee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.20
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    • pp.152-162
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    • 1975
  • Five barley varieties were compared under six 1evels of nitrogen fertilization and two methods of cultural management, conventional and drill seeding. The increase in grain yield and nitrogen content of the leaves showed a significant linear regression from added increaments of nitrogen in Haganemugi and Olbori, particulary under drill seeding. The other varieties resulted in various degrees of lodging and no significant increases in yield. The spike number per square meter was the major component of yield, but when the spike number per square meter was sufficient, 1000 grain weight was equally as important as a component of yield.

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Effects of Seeding Dates on Lodging in Water Seeding of Rice (벼 담수표면 직파재배에서 파종기가 도복에 미치는 영향)

  • 송동석;김용재;이성춘
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.2
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    • pp.157-167
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    • 1996
  • The method of direct seeding on flooded paddy surface in rice is known to be the most labor saving cultural practice in rice. However, this method has a problem in practical use such as severe lodging occurring at the reproductive growth stage. The objectives of this study were observated degree of field lodging and variation of lodging-related characteristics with different seeding dates. The number of seedlings per m$^2$ were from 91 to 144 plants, and seedling ratios were from ranged from 61.7% to 91.8%. Days from seeding to flowering were shortened from 5 to 15 days by the later seeding dates. Heading dates of Ilpumbyeo, Seoanbyeo, Daecheongbyeo and Donjinbyeo on June 9 showed slightly elapsed on the critical stable heading time from, August 28 to 29. The culm length was effective in longer clum varieties than semidwarf varieties. The degree field lodging (degree of lodging: 0~9< 9 : complete lodging) in Obongbyeo and S101 with semidwarf varieties were 0.17, whereas 1.25 in Dongjinbyeo with long culm. The lodging resistant varieties and later seeding dates shortened the length of fibrous in the clum, and thickened fibrous in the clum, respectively. Obongbyeo and Sl0l showed stronger resistance to field lodging. The lodging resistant varieties, Obongbyeo and Sl0l, showed lower values of lodging index from 1.03 to 1.15 than those of lodging susceptible varieties, Daecheongbyeo and Palgongbyeo ranged from 1.42 to 1.70. Bending moment with leaf sheath were greater in lodging resistant varieties (Obongbyeo and Sl0l),1510.0~1930.4g.cm, than those in the lodging susceptible varieties (Daecheongbyeo and Palgongbyeo), 1127.2~1287.6g.cm.

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'Hongan', a New Mid-Season Apple Cultivar (중생종 사과 '홍안(紅顔)' 육성)

  • Kwon, Soon-Il;Kim, Jung-In;Kim, Mok-Jong;Paek, Pong-Nyeol;Shin, Yong-Uk;Hwang, Jung-Hwan;Kang, Sang-Jo;Kim, Dae-Il;Choi, Cheol;Kang, In-Kyu
    • Horticultural Science & Technology
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    • v.29 no.6
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    • pp.655-658
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    • 2011
  • A new cultivar 'Hongan' was originated from an artificial cross between 'Fuji' and 'Jonathan' carried out at National Institute of Horticultural & Herbal Science in 1993. The cultivar was preliminarily selected among the elite siblings for its high fruit quality in 2002. After regional adaptability test at five districts for subsequent four years as 'Wonkyo Ga-32', it was finally selected in 2006. 'Hongan' is characterized by the following. Optimum harvest time is late September. Shape of the mature fruit at 309 g on mean weight is globosity with a light red skin on a greenish yellow ground and yellowish white flesh. The fruit contains favorable total soluble solids at $13.7^{\circ}Brix$ and an acidity at 0.28%. Safe storage period for the fruit is 3 weeks at room temperature. It is resistant to Bitter rot. 'Hongan' also reveals a physiological cross compatibility with leading cultivars such as 'Gamhong' and 'Tsugaru' in addition to its maternal parent 'Fuji'. Tree topology is semi-spreading with vigorous growth habit.

PILOT SCALE FISH PRODUCTION IN WATER RECYCLING SYSTEM (순환여과식 사육수정화 재사용방법에 의한 Pilot 규모의 어류양식시험)

  • KIM In-Bae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.13 no.4
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    • pp.195-206
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    • 1980
  • Fish were grown in a water recycling rearing system consisting of a filter system, of which the area is about $30\;m^2$ and the volume of filter gravels is about $15\;m^3$, 6 rearing and 2 supplementary tans about $7\;m^2$ of surface area each. The results for 180 days from April 18 to October 14,1980 are summarized as following: One rearing tank was used for main experiment stocked with an equal number, and weight of each Israeli strain and $F_1$, hybrid between this strain and Korean local strain of common carp. Gross total production was 461 kg with a net production of 395 kg, and the Israeli strain grew to about 8 times initial weight and the hybrid about 6 times. Based on an analysis of results of the above mentioned main experiment and the other miscellaneous fish grown in the remaining tanks, it was considered to be feasible to implement a commercial production in this system by improving parts of the system and adding a number of the units. A special problem seems to be an adoption of more effective aeration device when fish loading increases. A solid waste removal system was deviced by use of by-pass flow ana this system worked very efficiently in view of supply water economy. A serious problem encountered in this experiment was heavy outbreaks of the gill-fluke, Dactylogyrus sp. which was relatively easily eradicated with Dipterex or DDVP treatment in the first trials, but later on strains which were resistant to any of these chemicals appeared.

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Insecticidal Activities against Major Lepidopteran Pests and Culture Condition of Bacillus thuringiensis sp. aizawai collected in Korea (국내에서 선발한 Bacillus thuringiensis sp. aizawai 균주의 주요 나방류 해충에 대한 살충 활성 및 배양특성)

  • Lee, Sang-Guei;Choi, Kee-Hyun;Lee, Young-Su;Oh, Kyeong-Seok;O, Jeung-Hun;Choi, Sung-Won
    • The Korean Journal of Pesticide Science
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    • v.10 no.2
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    • pp.131-137
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    • 2006
  • This experiment was conducted to select prominent microorganisms with a good insecticidal activity among the ten species, which isolated from soil at the near of Chung-buk, Chung-nam, and Gang-won provinces and made protein crystal endotoxin. As a result, GB-413 strain was finally selected, which showed the high insecticidal activity against susceptible diamondback moth (Plutella xylostella), beet army worm (Spodoptera exigua) and tobacco cutworm (Spodoptera litura) as well as resistant diamondback moth strains. By modifying the cultivation process f.g. lowing the glucose concentration at early cultivation stage and adding the carbon after inducing the spores, the percentage of making spore as well as the number of active spore were increased and the time for cultivation and spore forming was reduced without a reduction of insecticidal activity. These results were not only applied successfully for the optimized cultivation process for a fermentation tank containing five tons capacity, but also improved the possibility of mass cultivation for commercial production.

A Study on the Basic Design and its Characteristics of 50ft-class CFRP Cruise Boat (50피트급 탄소섬유강화복합재료 크루즈 보트의 기본설계 및 특성)

  • Oh, Dae-Kyun;Lee, Chang-Woo;Jeong, Uh-Cheul;Ryu, Cheol-Ho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.6
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    • pp.674-680
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    • 2013
  • As the range of marine leisure activity gradually expands to ocean-going, a habitable cruise boat has been getting the limelight. Advanced countries in the marine leisure industry in Europe and North America have already secured their competitiveness in designing and building cruise boats by elegant design, ergonomic structure and fuel efficiency through the adoption of light-weight hull materials. In contrast, mostly small power boats are developed and built in Korea, and GFRP take up the most of hull materials. This study inquired into the design and characteristics of a 50ft-class CFRP that ocean-going is possible. The hull-form of the CFRP cruise boast were analyzed to propose a hull form for the designed ship (MMU-C.B), and based on that, the design model of the MMU-C.B was built. Finally, the MMU-C.B's characteristics of the resistance performance and hull-planing were found by comparative reviews with the results of model tests of GFRP pleasure yachts.

Effect of Bacillus subtilis C4 and B. cereus D8 on Plant Growth of Canola and Controlling Activity Against Soft Rot and Stem Rot (Bacillus subtilis C4와 B. cereus D8에 의한 유채의 생육증대 및 무름병과 균핵병 방제효과)

  • Lee, Jae-Eun;Lee, Seo-Hyeun;Park, Kyung-Soo;Park, Jin-Woo;Park, Kyung-Seok
    • The Korean Journal of Pesticide Science
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    • v.13 no.4
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    • pp.275-282
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    • 2009
  • The effect of two plant growth-promoting rhizobacteria (PGPR) on plant growth and systemic protection against soft rot disease and stem rot disease of canola (Brassica napus), caused by Erwinia carotovora and Sclerotinia sclerotiorum was investigated in a laboratory and a greenhouse. Selected PGPR strains C4 and D8 were treated to canola seeds by soaking. Strains C4 and D8 significantly not only increased plant height and root length about 74% and 40.3% and also reduced disease severity of soft rot disease by 80% by C4 and D8 respectively, compared to the control. Especially strain C4 showed antifungal activity against 6 fungal pathogens, S. sclerotiorum, Rhizoctonia solani, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici and Colletotrichum acutatum. In greenhouse experiment, the seed treatment of both of them increased plant height, leaf width and leaf length of canola plant to 19.5% and 24.9%, 11.3% and 15.3%, and 14.1% and 20.7% by C4 and D8, respectively, and reduced disease severity of S. sclerotiorium. These results indicate that these two PGPR strains can decrease disease severity and increased plant growth under greenhouse condition. Therefore, these two bacteria have a potential in controlling Sclerotinia stem rot of canola. These strains have to investigate under field condition to determine their role of antibiosis, induced systemic resistance and plant growth promotion on canola.